#include<math.h>
#include<stdio.h>
main()
{
    int m,i,k;
    int flag=1;
    printf("Please enter a number:");
    scanf("%d",&m);
    k=(int)sqrt(m);
    for(i=2;i<=k&&flag;i++)
    {
        if(m%i==0)flag=0;
    }
    if(flag)
    {
        printf("Yes!\n");
    }
    else
    {
        printf("No!\n");
    }
    printf("Progran is over!\n");
}
